In the oil and gas industry, hydrocarbons are accessed via a wellbore to provide a fluid flow path to a processing facility. Some of these hydrocarbon resources are located under bodies of water, such as lakes, seas, bays, rivers and/or oceans, while others are located at onshore locations. To transfer hydrocarbons from such locations, a pipeline and/or one or more different vessels (e.g., ship or tanker trucks) may be utilized through various segments from the wellbore and the processing facility.
Additionally, hydrocarbons may be transferred from a production region to another region for consumption/processing into hydrocarbon-based products or from one hydrocarbon storage location to another. Transfer of hydrocarbons between such locations often requires one or more different vessels and routes over bodies of water, such as lakes, seas, bays, rivers and/or oceans.
Offshore leaks and/or spills may be problematic due to the hydrocarbons being released into a body of water. Typically, the hydrocarbons may form a slick on the surface of the water, which may be referred to as an oil slick. Various response techniques may be utilized to manage the oil slick. For instance, chemicals may be added to the oil slick and mixed with the oil slick to break apart the hydrocarbons. In other situations, the oil slick may be ignited to burn off the oil slick or mechanical recovery may be utilized to capture the hydrocarbons.
In managing an oil slick, one response option for a marine oil spill is to ignite and burn the oil slicks in situ. In situ burning (ISB) involves oil slicks that are thick enough to burn. Typically, oils naturally spread after spilling on a large water surface to a thickness that is too thin to sustain combustion. Typically, oil slicks have to be greater than 1 millimeter (mm) to sustain combustion. This is because oil slicks thinner than 1 mm, in general, lose too much heat to the water column and self-extinguish. Oil slicks thicker than 1 mm provide enough insulation from heat loss to the water below so that combustion can be maintained once a slick is ignited. The thicker an oil slick results in a more efficient combustion because the burn continues until the oil slick thins to about 1 mm or less.
Conventional approaches for ISB is to use fire-resistant booms. These booms are large pieces of equipment that involve significant amounts of time to transport from a stockpile location to an oil spill site. This time delay may be further compounded when the booms are transported between individual oil slicks, which may occur if the oil slick breaks into different sections. The challenge of transporting fire-resistant booms combined with limited availability has resulted in ISB being an operational tool for a limited amount of offshore oil spills. The problem with convention methods is that the response time associated with booms is not efficient enough to provide a rapid response for conducting ISB.
Another response option is to use herders instead of physical booms. Herders are composed of surfactants dissolved in a solvent. Spraying the herder on the water around the perimeter of an oil slick changes the surface tension of the water (from about 70 dynes/centimeter (cm) to <40 dynes/cm) thereby causing the oil to contract into a smaller area. This contraction results in the oil slick becoming thicker. The current process for spraying herders is to load a spray application system and a supply of herders onto a boat. The boat then moves to an oil spill location and applies the herder to the water surface around the perimeter of the oil slick. For the oil slick to have maximum contraction and thickening, it is important to spray herder onto the water surface avoiding overspray onto the oil itself.
As the management of hydrocarbon leaks and spills is a time consuming operation, a need exists to enhance operations to manage hydrocarbon releases with enhanced methods and systems. In particular, a need exists for a method that is more efficient and may be deployed rapidly to different locations to conduct ISB of oil slicks.